I believe that the most expensive U.S. Penny is the 1793 "strawberry leaf" variety. It is worth so much because it is so rare (there are only 5 known). In F-12 condition it is worth $414,000. If you don't know much about numismatics, let me tell you F-12 condition is extremely crappy. Numismatist grade coins on a scale of 1 to 70, the higher the number the better condition it is in. So if this penny sells for $414,000 in F-12, imagine how much it would sell for in an even better condition!